Liquid propellant for small caliber gun



p 1967 E. 5. DORSEY, JR, ETAL QUID PROPELLANT FOR SMALL CALIBER GUN 2 Sheets-Sheet 1 Filed March 25, 1953 //VVENTORS Edwnr d BDnnsey, Ur. Bernard A Nieme'i E1 331:5 EnE' T. Fleiauhhuuen ATTOENEYS and/8.

United States PatentOfitice 3,313,208 LIQUID PROPELLANT FOR SMALL CALIBER GUN Edward G. Dorsey, .irz, Bernard A. Niemeier, and Eugene T. Fleischhauer, Richmond, Va., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Army Filed Mar. 25, 1953, Ser. No. 344,652

11 Claims. (Cl. 89-7) This invention relates generally to ordnance, and in particular to a novel system for propelling projectiles from gun barrels or tubes.

Our invention consists of a method whereby self-igniting chemicals may be intimately intermixed so that their spontaneous reaction produces a pressure for projectile ejection and flight. It will be understood that in the specification and in the claims appended hereto the word hypergolic is intended to be used as defined in the Defense Departments Glossary of Guided Missile Terms, Capable of igniting spontaneously upon contact.

It is a broad object of our invention to improve on the weapons now in use. It is a further and more particular object of our invention to provide a system for propelling projectiles in which highly reactive liquid chemicals are used in place of the usual solid propellants.

It is a still further object of our invention to provide a reactive chemical weapon which is safe to operate and reliable in use.

Other objects of the invention will be evident from the following description and the appended drawings in which:

FIGURE 1 is a fragmentary longitudinal section of a preferred embodiment of our novel weapon.

FIGURE 2 is a view taken on lines 22 of FIGURE 1 and looking in the direction of the arrow.

FIGURE 3 is a fragmentary longitudinal section of another species of our invention.

FIGURE 4 is a fragmentary longitudinal section of still another species of our invention.

Referring now to the drawings wherein like reference characters indicate like parts and particularly to FIG- URES 1 and 2, reference character 1 indicates a gun barrel of conventional design threaded or otherwise firmly affixed to breech 2 which has a longitudinal chamber aligned with the barrel for the reception of a projectile 3. Two cavities 4 and 5, respectively, are formed in the breech as is best seen in FIGURE 2 and serve as main firing reservoirs for the several hypergolic components which constitue the propellent charge. The volumes of the cavities can be selected as propellant metering devices. Plugs 6 and 7 are threaded into the several cavities and serve to contain spring loaded ball valves 8 and 9 substantially as shown. Pipes 10 and 11 connect the valves with the main storage tanks for the hypergolic fluids (not shown). A pilot or triggering feed system is connected to each of the firing reservoirs 4 and for a purpose that will presently appear. As is revealed in FIGURE 1 an auxiliary plug 12 is threaded into block 2 and contains a spring loaded valve 13 closing the end of pipe 14 which is joined to pipe or otherwise connected to the main storage tank holding the reactant fiuid that normally is led into reservoir 4. A passage 15 extends downward from the plug and connects with a chamber 16 extending normal thereto and having a narrow portion 17 opening into reservoir 5. A spring loaded piston 18 and rod adapted for external actuation are slidably received within chamber 16 and the forward motion of piston 18 is arrested by spring loaded ball valve assembly 19. From a point at or near the bottom of reservoir 5 extends bore 20 leading.

through valve assembly chamber 21 to passage 22 which opens into the rearward portion of the projectile receiv- 3,313,268 Patented Apr. 11, 1967 ing chamber. It will be understood that an indentical pilot feed system (not shown) is provided for reservoir 4.

In operation two reactive fluids which may be called fuel and oxidant and can be for example, hydrazine with hydrogen peroxide, or hydrazine with nitric acid are separately stored in their respective external tanks. One reactant is pumped into reservoir 4 and the other into reservoir 5 until they are full whereupon the spring loaded valves effectively seal the fluid therein. The pumping pressure also forces a minute amount of the reactants into the opposed pilot feed systems so that reservoir 5 may hold the fuel and the pilot system connected thereto will hold the oxidant while reservoir 4 holds the oxidant and its pilot system contains a small amount of fuel. Triggering of the firing cycle is accomplished by moving the two pilot pistons forward by any suitable mechanical or electrical means. This motion forces the pilot fuel through the valves and into the firing reservoirs whereby a chemical reaction takes place accompanied by emission of heat and pressure limited only by the amount of pilot fluid injected. The pressure built up by the reaction forces the fluids down their respective passages and into a combustion chamber behind the projectile. When the main hypergolic fluids meet in the chamber a' violent reaction takes place whereby the projectile is forced down the barrel and started on its trajectory.

Our invention is not of course limited to the specific examples of fuel and oxidant enumerated above but contemplates the utilization of any and all substances and compounds that react spontaneously and violently upon contact including a monopropellant such as nitro-methane or methyl acetylene with a catalyst.

An important variant of our invention is revealed in FIGURE. 3 wherein reference character 1 indicates the gun barrel having annular contact members 23, 24, and 2 is the breech. A longitudinal passage in the breech receives a housing 26 having a cavity therein to hold spring valve 27 adapted to yieldingly close bore 28 which is connected by pipe 23 to a storage tank.- A plug 30 is threadedly held in the housing and has formed therein passages 31 leading to a combustion chamber 32 formed immediately to the rear of a projectile indicated generally as 33.

The projectile, which will now be described, has annular rings 34=and 35 secured thereto adapted to engage contact members 23 and 24 substantially as shown. A squib 36 is housed within the aforesaid parts of an inner chamber 37 and is electrically connected to an external source of electrical energy through leads 38 and 39.

The middle portion of the projectile is of a reduced di-.

ameter whereby an annular volume 40 is formed.

Frangible plugs 41 are held in holes communicating be-; tween inner chamber 37 and volume 40 and a frangible disc 42 is held at the rear portion of the chamber substantially as shown. It is intended to pre-load the projectile with one of the reactants (usually a fuel) which com-- pletely fills the internal chamber 37 and is in intimate contact with the squib housed therein.

In operation the preloaded projectile is inserted by means not shown, into the firing position in the weapon and the other reactant is admitted under pressure from pipe 29 through passages 31 and into chamber 32 whereupon it fills volume 40 and completely surrounds the preloaded reactant. When the squib is fired by external triggering means the frangible plugs 41 are shattered and the several reactants mix at the head of the fuel and oxidant columns. The pressure thus generated results in expulsion of the components to the rear and into the combustion chamber where they mix and a violent reaction takes place to expel the projectile. After the discharge another projectile may be rapidly inserted by automatic means if desired to complete the cycle and ready the gun for another round.

A still further variant of our invention is illustrated in FIGURE 4 wherein breech block 2 has a longitudinal passage therethrough to receive at the forward end thereof barrel 1. A projectile 3 is frictionally held aligned with the barrel for motion therein when the pressure in chamber 43 reaches a predetermined value. The breech block passage has a portion of reduced diameter 49 to slidably receive the enlarged head of hollow piston 50. Passages 52 radiate from the internal cavity 53 to the outer periphery of the piston head and passages 56 lead from the internal cavity radially outward for a purpose that will presently be explained. A plug 54 is threaded into the rear end of the passage and serves to receive spring loaded valve 55 and to act as a lateral guide during piston motion. A spring loaded valve 57 is threaded into the breech block and leads into the annular volume 58 formed between the piston and the block.

In operation one of the reactants for example an oxidant is pumped from a storage tank and forced through valve 55 to fill the volume 53. The other reactant is pumped from its tank and forced through valve 57 to fill volume 58. The gun is triggered by moving piston 50 forward by any suitable mechanical or electrical system whereby passages 52 open into chamber 43, volume 58 is opened into chamber 43 around the piston and passages 56 connect volumes 53 and 58. A minute quantity of the reactants will move through the passages 56 and a chemical reaction accompanied by a pressure rise occurs in the area adjacent the passages. This pressure forces the contents of volume 58 forward around the piston and into chamber 43 and the contents of volume 53 through passage 52 into chamber 43 Where the reactants mix and expel the projectile.

In a general manner, while we have, in the above description disclosed what we deem to be practical and efficient embodiment of the present invention, it should be well understood that we do not wish to be limited thereto as there might be changes made in the arrangement, disposition, and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

What we claim is:

1. A gun comprising a breech casing, a barrel affixed to said casing, a projectile in said casing and aligned with the said barrel, a propellant comprising an oxidant and a fuel, said oxidant and said fuel contained in separate chambers formed in said gun, means including a passage to admit a predetermined quantity of fuel into the oxidant chamber, a passage to admit a quantity of oxidant into the fuel chamber to pressurize each said fuel and oxidant chambers, and means forming passages from the chambers to intermingle the said oxidant and the said fuel behind the said projectile and detonate spontaneously.

2. A firearm comprising in combination a breech casing, a barrel aflixed to the said casing, a projectile in said casing and aligned with said barrel, a combustion chamber, a propellant to expel said projectile, said propellant comprising an oxidant and a fuel, an elongated hollow member longitudinally movable within said casing, said oxidant contained in a first chamber Within said hollow member, said fuel contained in a second annular chamber in said casing surrounding said hollow member between said member and said casing, means forming a plurality of passages at the rear of said member, means forming a plurality of passages at the front of said member whereby movement of said member in a direction toward the said barrel joins the said first and second chambers at the rear thereof to effect a limited expansion in both chambers to expel the fuel and the said oxidant into the said combustion chamber.

3. A fire-arm comprising in combination a breech casing, a barrel afiixed to the said casing, a projectile in said casing and aligned with said barrel, a combustion chamber in said casing, a propellant comprising an oxidant and a fuel, an elongated member longitudinally movable within said casing, said oxidant contained in a first chamber within said member, said fuel contained in a second annular chamber formed between said member and said casing, means forming a plurality of passages at the rear of said member, means forming a plurality of passages at the front of said member whereby movement of said member in a direction toward the said barrel joins the said first and second chambers for pressurization thereof and expulsion of the fuel and oxidant into the said combustion chamber.

4. A firearm comprising in combination a breech casing, a barrel affixed to said casing, a projectile in said casing and aligned with said barrel, a combustion chamber, a propellant to expel said projectile, said propellant comprising an oxidant and a fuel, an elongated hollow member axially movable within said casing, said oxidant contained in a first chamber within said hollow member, said fuel contained in a second annular chamber in said casing surrounding said hollow member, means forming a plurality of normally closed passages at the rear end of said hollow member whereby axial movement of said hollow member in a direction toward said barrel uncovers the rear passages for effecting a limited degree of intermingling of oxidant and fuel to pressurize both chambers, and means comprising a plurality of normally closed passages at the front end of said hollow member whereby the oxidant is forced from its chamber through said front passages under said internally developed pressure and simultaneously fuel is forced from its chamber to pass said hollow member to intermingle with the fuel in the combustion chamber and detonate therein spontaneously.

5. A liquid propellant gun comprising a breech casing, a barrel affixed to said casing, a projectile in said casing aligned with said barrel, a combustion chamber in said casing behind said projectile, a hypergolic propellant comprising an oxidant and a fuel contained in separate chambers in said gun, injection means adapted to admit a predetermined quantity of fuel into said oxidant chamber and a predetermined quantity of oxidant into said fuel chamber to pressurize each said fuel and oxidant chambers, and passages between each said fuel and oxidant chamber and said combustion chamber.

6. A gun comprising a breech casing, a barrel afiixed to said casing, a combustion chamber in said casing communicating with said barrel, a fuel chamber in said casing containing a hypergolic fuelfan oxidant chamber in said casing containing a hypergolic oxidant, pressurizing means operatively associated with said fuel and oxidant chambers, said pressurizing means injecting a predetermined quantity of fuel into said oxidant chamber and a predetermined quantity of oxidant into said fuel chamber to pressurize each said fuel and oxidant chamber, and passages connecting said fuel and oxidant chambers to said combustion chamber whereby the fuel and oxidant are forceably intermixed in said combustion chamber.

7. In a hypergolic propellant gun a breech casing, a plurality of firing reservoirs in said breech, an oxidant in half of said reservoirs and a fuel in the remainder of said reservoirs, a triggering feed system for said reservoirs to expel the said oxidant and fuel therefrom under pressure, said system comprising a fuel chamber having passages connected with said oxidant reservoirs, an oxidant chamber having passages connected with said fuel reservoirs and means to discharge the fuel and oxidant in said chambers into said reservoirs, and passage means to conduct said fuel and oxidant in said reservoirs to a combustion chamber for spontaneous combustion therein.

8. A liquid propellant firearm comprising a breech casing, a barrel affixed to said breech casing, a projectile in said casing aligned with said barrel, a hypergolic propellant comprising an oxidant and a fuel, separate reservoirs, one of which is within said projectile, containing predetermined quantities of said oxidant and said fuel, means to intermix said predetermined quantities of saidoxidant and said fuel in a combustion chamber including a first passage connecting saidoxidant reservoir with said combustion chamber and a second passage connecting said fuel reservoir with said combustion chamber, normally closed conduit means associated with the reservoir in said projectile and the other said reservoir to connect said fuel reservoir with a source of said oxidant and said oxidant reservoir with a source of said fuel, triggering means initiated on firing of said gun to open said normally closed conduits and allow intermixing of a small quantity of fuel and oxidant to pressurize said fuel and oxidant reservoirs and force the predetermined quantities of said oxidant and said fuel through said first and second passages into said combustion chamber.

9. The firearm as in claim 8 wherein said fuel chamber is formed in said projectile and said oxidant chamber is formed in said casing concentric with said fuel chamber in said projectile.

10. The firearm as in claim 8 wherein said fuel chamber is formed in said projectile and said oxidant chamber is formed concentric with said projectile and between said projectile and said casing when said projectile is in said casing.

11. A liquid propellant gun comprising a breech casing, a barrel affixed to said casing, a projectile in said 2 casing aligned with said barrel, a hypergolic propellant comprising an oxidant and a fuel, separate reservoirs containing predetermined quantities of said oxidant and said fuel, means to intermix said predetermined quantities of said oxidant and said fuel in a combustion chamber including a first passage connecting said oxidant reservoir with said combustion chamber and a second passage connecting said fuel reservoir with said combustion chamber, normally closed conduit means associated with said oxidant and said fuel reservoirs to connect said fuel reservoir with a source of oxidant and said oxidant reservoir with a source of said fuel, means initiated on firing said gun to open said normally closed conduits and allow intermixing of a small quantity of fuel and oxidant to pressurize said oxidant reservoir and said fuel reservoir and force said predetermined quantities of said oxidant and said fuel through said first and second passages for intermingling and spontaneous ignition in said combustion chamber.

References Cited by the Examiner UNITED STATES PATENTS 2,129,875 9/1938 Rost 89-7 20 2,573,471 10/1951 Malina et al.

FOREIGN PATENTS 1,003,687 11/1951 France.

405,645 1/ 1934 Great Britain.

SAMUEL FEINBERG, Primary Examiner. 

1. A GUN COMPRISING A BREECH CASING, A BARREL AFFIXED TO SAID CASING, A PROJECTILE IN SAID CASING AND ALIGNED WITH THE SAID BARREL, A PROPELLANT COMPRISING AN OXIDANT AND A FUEL, SAID OXIDANT AND SAID FUEL CONTAINED IN SEPARATE CHAMBERS FORMED IN SAID GUN, MEANS INCLUDING A PASSAGE TO ADMIT A PREDETERMINED QUANTITY OF FUEL INTO THE OXIDANT CHAMBER, A PASSAGE TO ADMIT A QUANTITY OF OXIDANT INTO THE FUEL CHAMBER TO PRESSURIZE EACH SAID FUEL AND OXIDANT 